It is well known that high molecular weight, aromatic polycarbonate resins have high impact strength below a critical thickness of between about 1/2 and 1/4 inches. Above this average thickness, the impact strength of such polycarbonate resins is low. It is also known that the impact strength of these polycarbonate resins decreases rapidly as temperatures decrease below about -5.degree. C. as well as after aging at elevated temperatures above about 100.degree. C. These characteristics limit the fields of applications of these resins. Thus, unmodified polycarbonates are not practical for use at low or high temperatures, particularly when good impact strength is required. Therefore, it is desirable to improve the impact strength of polycarbonate resins at bogh low and high temperatures as well as improve their aged impact strength and thereby expand the fields of application of such resins.
Polycarbonate compositions having improved impact strength at both high and low temperatures as well as improved aged impact strength are disclosed in co-pending applications Ser. Nos. 69,822; 69,823; 69,824; and 69,825 all of which were filed Aug. 27, 1979 and are now respectively U.S. Pat. Nos. 4,263,415; 4,260,693; 4,263,416; and 4,245,058. as well as in co-pending application Ser. Nos. 132,330; 132,325; 4,132,190 filed of even date with this application and are now respectively U.S. Pat. Nos. 4,320,212; 4,251,674; and 4,255,534.